1. Field of the Invention
This invention relates generally to high speed continuous motion packaging machinery designed for filling relatively small containers with a particulate product or material. The invention relates more particularly to filling equipment of this character adapted to accurately dispense, into pouches formed of flexible packaging material or other narrow mouth containers, a particulate product which may contain fatty or gummy ingredients in a relatively high proportion.
The invention is disclosed herein in an embodiment constituting a modification of a commercially available and widely-used machine known as the Pouch King, manufactured and sold by the R. A. Jones & Company, Inc. of Cincinnati, Ohio. The basic features of such machine are disclosed in U.S. Pat. No. 3,453,799 to Charles E. Cloud et al. issued July 18, 1969. Additional patents disclosing various features of said machine are shown in U.S. Pat. Nos. 3,563,001 issued Feb. 16, 1971 and 3,478,492 issued Nov. 18, 1969, to C. E. Cloud et al.
A typical filler machine of this character may comprise a turret-like structure, the upper section of which constitutes a continuously rotating turntable onto the surface of which product is continuously deposited in an accurately metered amount. The lower section of said turret carries around its sides a continuous web of packaging material which has been formed into a succession of open top pouches by a series of folding and/or sealing steps performed in earlier stages in the overall packaging system. Arranged around the periphery of the turntable is a series of funnel-shaped cavities into which the product, deposited as a ribbon on the rotating turntable, is deflected seriatim and gradually to avoid plugging the necessarily small diameter spouts leading from each of said cavities. Utilizing a turret structure in this manner for a filler apparatus allows sufficient time in the overall packaging operation for the gradual filling of pouches while still permitting web feed to proceed at speeds compatible with that of other components of the overall system.
In this typical construction the carefully metered product, laid down on the rotating turntable in a ribbon formation, is gradually deflected by a fixed plow positioned immediately above the turntable surface and extending from the metering block to the periphery of the table in an arc having a radius somewhat greater than that of the turntable. In this manner the product is plowed and worked starting from the inner edge of its ribbon formation until as the turntable continues rotating, the entire ribbon width of it is eventually pushed into the peripherally arranged cavities which are in direct communication with underlying pouches.
It will be understood that in such apparatus the uniformity of fill weight is dependent on the uniformity of the ribbon of product leaving the metering block together with the uniformity with which the product is plowed or deflected into the cavities at the periphery of the turntable. When the inner edge of the ribbon encounters the stationary plow it is retarded by the frictional engagement therewith while the outer edge continues moving at the velocity of the turntable. This velocity combined with the folding action of the plow produces a complexity of product movements that must be maintained in a steady state condition or dynamic balance to guarantee constant uniform fill weights. Any irregularities in the face of the plow or any changes in the frictional forces between the product and the plow or the product and surface of the turntable can cause a momentary buildup and subsequent sudden release of irregular or abnormal amounts of product to result in unacceptable weight variations among the filled pouches.
Furthermore, with such apparatus some product inevitably gets beneath the plow and smears onto the table surface, occasionally breaking away in pieces large enough to plug the fill spouts. This difficulty is encountered particularly with products containing fats, oils or gums.
2. Description of the Prior Art
Another approach known to the art for filling flexible containers with a measured amount of granular product involve first filling a measuring cup or receptable up to a predetermined level and then subsequently discharging the product from the cup in its entirety. One example of such approach is shown in patent to Rose et al. U.S. Pat. No. 2,657,832. Another example is disclosed in the patent to Thurlings, U.S. Pat. No. 3,042,260. A still further example is disclosed in patent to Lense U.S. Pat. No. 3,265,251. In each of these various examples the product is deposited in the respective measuring cups by movement thereof from the supply hopper by means acting in a plow-like manner, thus giving rise to problems of the sort hitherto mentioned in conjunction with the steady state or dynamically stable approach of the aforementioned patents to Cloud et al. Furthermore, the approach of premeasuring the product by filling a measuring cup to its capacity before it can be discharged into the ultimate pouch involves additional time factors and also additional mechanical devices which are hindrances to achieving a high operating efficiency such as can be achieved when the measuring function is accomplished by mechanism operating to feed the product in a steady stream for division into separated and measured amounts by close coordination of the feed rate with the advance of the web, all in a steady state condition wherein a dynamic balance between the operation of the respective parts is maintained.